Amorphous and Microcrystalline Silicon Deposited by Low-Power Electron-Cyclotron Resonance Plasma-Enhanced Chemical-Vapor Deposition
スポンサーリンク
概要
- 論文の詳細を見る
The structural and optoelectronic properties of intrinsic amorphous silicon (a-Si:H) and microcrystalline silicon ( µc-Si:H) deposited using electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) with a microwave power of 150 W were studied as a function of the ECR source-to-substrate distance, d ss, process pressure, hydrogen dilution and substrate temperature. Hydrogen was used as the excitation gas and silane was injected into the main chamber. Deposition rates show a maximum as a function of the deposition pressure. For d ss=6 cm this maximum occurs between 5 and 10 mTorr. ECR-deposited a-Si:H films show a high Tauc bandgap (∼1.9 eV), low dark conductivity (∼10-11 Ω-1 cm-1), relatively high Urbach energy (≥55 meV) and high defect density (≥5×1015 cm-3) compared with a-Si:H grown by RF glow discharge. Hydrogen evolution and infrared spectroscopy reveal the presence of voids and/or columnar structure. The transition from amorphous to microcrystalline silicon occurs under conditions of high hydrogen dilution, low deposition pressure, and low d ss. The higher the hydrogen dilution, the lower the substrate temperature needed to achieve µc-Si:H. Raman spectra of the µc-Si:H suggest small grain size ( ∼4 nm) and crystalline fraction (∼60%). A growth model is proposed that includes silane excitation both by the ECR electrons and by the excited hydrogen species.
- Publication Office, Japanese Journal of Applied Physics, Faculty of Science, University of Tokyoの論文
- 1997-01-15
著者
-
Sousa R
Univ. Texas Health Sci. Center Texas Usa
-
Conde João
Department of Materials Engineering, Instituto Superior Tecnico, IST Av. Rovisco Pais, 1096 Lisbo
-
Schotten Volker
Instituto de Engenharia de Sistemas e Computadores, INESC Rua Alves Redol 9, 1000 Lisboa, Portuga
-
Arekat Safwan
University of Bahrain, College of Science, Physics Department P.O. Box 32038, Bahrain
-
Brogueira Pedro
Department of Physics, Instituto Superior Tecnico, IST Av. Rovisco Pais, 1096 Lisboa Codex, Portu
-
Sousa Rui
Department of Physics, Instituto Superior Tecnico, IST Av. Rovisco Pais, 1096 Lisboa Codex, Portu
-
Chu Virginia
Instituto de Engenharia de Sistemas e Computadores, INESC Rua Alves Redol 9, 1000 Lisboa, Portuga
-
Chu Virginia
Instituto De Engenharia De Sistemas E Computadores
-
Arekat Safwan
University Of Bahrain College Of Science Physics Department
-
Schotten Volker
Instituto De Engenharia De Sistemas E Computadores
-
Brogueira Pedro
Department Of Physics Instituto Superior Tecnico
-
Conde Joao
Department Of Materials Engineering Institute Superior Tecnico